'Appendix G: FORTRAN code for state variable analysis' (Energy Engineering, 2003), 'Power Systems Electromagnetic Transients Simulation', Chap. appendixg, pp. 389-394, DOI: 10.1049/PBPO039E_appendixg
IET Digital Library, https://digital-library.theiet.org/;jsessionid=74inn0p8fi23.x-iet-live-01content/books/10.1049/pbpo039e_appendixg